Method and apparatus for conditioning air in refrigerators



Nov. 6, 1934. 'c, G. VRETMAN METHOD AND APPARATUS FOR CONDITIONING AIR IN REFRIGERATORS Filed Dec. 2, 1935 Ell Fatented Nov. 6, 1934 NITED STATES PATENT OFFICE- METHOD AND APPARATUS FOR CONDI- '10 Claims.

This invention relates to improvements in methods and apparatus for conditioning air in refrigerators. The mechanical refrigerators now in use have a number of serious drawbacks which the producers have not yet been able to overcome, some of the most important of which are the accumulation of ice on the cooling coils, drying of the food, and accumulation of gases and odors exhaled by the food. When the moisture of the air is frozen out and deposited on the coils, the air naturally becomes very dry and its tendency to absorb moisture increases, especially upon becoming warmer. Naturally this air upon contacting with the food dries it and then, upon recirculation into contact with the cooling coils, deposits the absorbed moisture on the coils. In this way the coils soon become coated with a layer of ice or frost which acts as an insulator and impairs the efficiency of the cooling unit.

Among the objects of this invention are to provide a method and apparatus for conditioning air in refrigerators in which deposition of ice or frost on the refrigerating coils is avoided or automatically removed, to remove from the refrigerator odors and flavors of food and other gases exhaled by the food, to maintain the atmosphere in the refrigerator sufliciently moist at all times to prevent drying of the food, and to properly circulate the air in the refrigerator. in the drawing illustrating the invention: Fig. l is a vertical sectional view of a refrigerator according to the present invention with.

some parts partially broken away;

Fig. 2 is a vertical sectional view taken at right angles to Fig. 1 on line 2-2 of Fig. 1;

Fig. 3 is a horizontal sectional view on line 33 of Fig. l with somedetails omitted; and

Fig. 4 is a horizontal sectional view on line 4 -a of Fig. 1 showing the humidifier unit.

In the drawing, numeral 1 refers to box containing several shelves 2 and containing an ice freezing compartment 3 having coils not shown) maintained cold by conventional compressor or gas apparatus (not shown and per se forming no part of this invention). The walls of the ice freezing compartment are preferably of insulating material whereby the temperature in this compartment may be maintained much lower than the food compartment and the cooling of the food compartment is not dependent on the freezing coils of the ice compartment. The thorough insulation of the ice freezing compartment also prevents frosting on the outside of this compartment. The front of the ice com partment is provided with a hinged door'4 to further insulate the compartment and keep out I the air of the food compartment, thus minimizing frosting of the freezing coils while allowing access to the ice when desired. The food compartment is maintained cold by a set of coils 5 preferably located at the back and toward the top of the food compartment. These coils are conveniently maintained cold by the same compressor or gas unit as the above-mentioned ice freezing coils and may be connected in series after the ice freezing coils or in parallel with the freezing coils, in which case each set of coils is preferablyprovided with a separate expansion valve and temperature control mechanism. By either of these arrangements the temperature in the ice compartment may be maintained below freezing while the temperature of the coils of the food compartment may be maintained above freezing. By such arrangement, deposition of :5 ice on the freezing coils is avoided by isolation from the air, while ice on the food compartment coils cannot occur as their temperature is above freezing.

If desired, the size of the food' compartment 30 coils may be made smaller by using a lower temperature, even below freezing, in which case deposition of ice may occur, but since the coils .are freely exposed to the atmosphere of the food frosting will occur on the part of the coils outside the ice compartment, but on account of the fins 10, the large heat transfer area thereby exposed to the atmosphere of the food compartment will automatically defrost the coils and fins during cut-out periods.

A partition plate 6, preferably of insulating material, is disposed at the back of the food compartment but spaced from the rear wall. The food compartment cooling coils 5, previously mentioned, are positioned behind this partition 6. The partition plate does not extend the full height of the food compartment, but openings 8 and 9 at the top and bottom respectively are provided. At the side beneath the ice compartment the partition 6 is bent backwardly as at 7, thus completing the dividing off of an air treating compartment. The coils 5 may be provided with a plurality of fins 10 to increase the heat transfer from the air to the coils and to contact with a greater part of the air and to provide a greater surface upon which the moisture may deposit. These fins extend vertically and from front to back behind the partition 6, and the lower edges of the fins are formed pointed to provide drip points 11 for the moisture. Beneath these points a trough or gutter 12 extends from the ice compartment to the opposite side and has an opening into a drain pipe 13. Upon contact with the coils and fins the air becomes cooled below its dew point and a substantial part of its moisture precipitates and is deposited on the coils and fins and runs down into the gutter and out of the refrigerator through the drain pipe. A great part of the odors and gases exhaled from the food are dissolved in the precipitated moisture and also pass out with the moisture. Since the precipitated moisture isremoved from further contact with the air immediately after precipitatiom the possibility of recontamination by the same gases, odors or flavors is eliminated.

The cooled air in a somewhat purified and dried condition after contact with the cooling device passes downwardly by the influence of gravity and becomes somewhat warmer. In order not to cause excessive drying of the food, provision is made for replenishing the moisture content of the air with fresh clean gas-free water before return to the food compartment. To this end a. water trough 14 extends across the lower portion of the air treating compartment and a baflie plate 15 directs the air against the water in the trough. Water is supplied to the trough from a pipe 16 connected with the house mains. The humidifying device may be of any suitable kind and, as illustrated, may be simply the trough 14 and .a spray provided by one or more fine perforations 17 in the sides of pipe 16. The water may be supplied as a drip, a fine spray, injected through an atomizer or in the form of steam, and preferably in excess of the quantity that will be taken up by the air. A conventional constant level overflow weir or the like may control the level in the trough and the excess flows off into drain pipe 13. The air in its cooled, purified and rehumidified condition then passes back to the food compartment through bottom opening 9.

By this invention the air is kept in such condition that the food is not dried, the exhaled gases and odors are continually removed thus preventing contamination of one food by another, and it is unnecessary to put the refrigerator outof operation for defrosting the food compartment cooling coils.

I claim:

1. In a refrigerator, 8. box, partition means separating said box into a food compartment, a freezing compartment and an air treating compartment, a refrigerating element in the air treating compartmentfor cooling the air and precipitating moisture therefrom, means for removing the precipitated moisture from further contact with the air, and means for humidifying the air with fresh moisture after leaving the refrigerating element.

2. In a refrigerator,v a box, partition means dividing the box into a food compartment and an air treating compartment, the partition means having an opening at the upper portion for entrance of air to the air,treating compartment from the food compartment, and an opening at the bottom portion for retum of the air to the food compartment, means in the air treating compartment for cooling the air and precipitating moisture therefrom, means for removing the precipitated moisture from further contact with the air, and means for humidifying the air with fresh moisture after leaving contact with the precipitated moisture.

3. In a refrigerator, 'a box, partition means dividing the box into a food compartment and an air treating compartment, the partition means having an opening at the upper portion for entrance of air to the air treating compartment from the food compartment, and an opening at the bottom portion for return of the air to the food compartment, a coil provided with heat transfer fins in the-air treating compartment for cooling the air and precipitating moisture therefrom, means for removing the precipitated moisture from further contact with the air, and means for humidifying the air with fresh moisture before return to contact with food in the food compartment.

4. In a refrigerator, a box, partition means dividing the box into a food compartment and an air treating compartment, the partition means having an opening at the upper portion for entrance of air to the air treating compartment from the food compartment, and an opening at the bottom portion for return of the air to the food compartment, a coil in the air treating compartment for cooling the air and precipitating moisture therefrom, a moisture c01- lecting gutter beneath the coils, a drain pipe from the gutter for removing the precipitated moisture from further contact with the air, and means beyond the gutter for humidifying the air with fresh moisture before return to contact with food in the food compartment.

5. In a refrigerator, a box, partition means dividing the box into a food compartment and an air treating compartment, the partition means having an opening at the upper portion for entrance of air to the air treating compartment from the food compartment, and an opening at the bottom portion for return of the air to the food compartment, a coil provided with heat transfer fins at the upper portion of the air treating compartment, a moisture collecting gutter beneath the coils and fins, a drain pipe from the gutter for removing precipitated mois- 12 ture from further. contact with the air, and means beyond the gutter for humidifying the air with fresh moisture before return to contact with foodin the food compartment.

6. In a refrigerator, a box, partition means dividing the box into a food compartment and an air treating compartment, the partition means having an opening at the upper portion for entrance of air to the air treating compartment from the food compartment, and an opening at the bottom portion for return of treated air to the food compartment, a cooling pipe at the upper portion of the air treating compartment, fins in contact with the pipe and disposed transversely thereto, said fins being pointed at their lower ends, a water collecting gutter bemeans having an opening at the upper portion for entrance of air to the air treating compartment from the food compartment, and an opening at the bottom portion for return of treated air to the food compartment, means at the upper portion of the air treating compartment for cooling the air and precipitating moisture therefrom, means for removingthe precipitated moisture from further contact with the air, and humidifying means below the moisture removing means for humidifying the air with fresh moisture before return to the food compartment.

8. In a refrigerator, a box, partition means dividing the box into a food compartment and an air treating compartment, the partition means having an opening at the upper portion for entrance of air to the air treating compartment from the food compartment, and an opening at the bottom portion for return of treated air to the food compartment, means at the upper portion of the air treating compartment for cooling the air and removing moisture therefrom a drain pipe for conducting the precipitated moisture from the refrigerator out of further contact with the air, humidifying means below the air cooling means for supplying fresh moisture to air, a water supply conduit for said humidifying means, said drain pipe also conducting excess water from the humidifying means out of the refrigerator.

9. In a refrigerator, an insulated box, partitions separating the inside of the box into a food compartment, an air treating compartment, and a freezing compartment, said partitions having openings providing communication between the food compartment and air treating compartment at the top and bottom, a cooling pipe at the top portion of the air treating compartment and having transverse heat transfer fins in contact therewith, said fins being downwardly pointed, a water collecting gutter beneath the fins, a drain pipe connected with said gutter for removing the collected moisture from further contact with the air, a water trough with humidifying means beneath the gutter for humidifying the air with fresh moisture, a water supply conduit for said humidifying means and trough, said trough being connected with the drain pipe, and a baflie for directing air into contact with the humidifying means.

10. The method of conditioning air in a food refrigerator comprising circulating the air in the refrigerator, precipitating moisture from the air by chilling to-remove contaminating matter, immediately removing the precipitated moisture from further contact with the air, and thereafter rehumidifying the air with fresh uncontaminated moisture to prevent drying of the food and absorbing further contaminating matter exhaled from the food.

CARL G. VRETMAN. 

